:root {
    --bg-dark: #121212;
    --hero-bg: #2d2d2d;
    --primary-lime: #8fbd43;
    --text-white: #ffffff;
    --text-muted: #a0a0a0;
    --card-bg: #ffffff;
    --input-bg: #f5f5f5;
    --border-color: #e0e0e0;
    --negative-red: #ff4d4d;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: #f8f9fa;
    color: #333;
    line-height: 1.6;
}

/* Header */
header {
    background: #fff;
    padding: 1rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.logo img {
    height: 40px;
    display: block;
}

footer a {
    color: inherit;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

.nav-btns {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 0.5rem 1.2rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    transition: background 0.2s;
}

.btn-outline {
    border: 1px solid #333;
    color: #333;
}

.btn-solid {
    background: #333;
    color: #fff;
}

/* Hero Section */
.hero {
    background-color: var(--hero-bg);
    padding: 4rem 10%;
    text-align: center;
    color: var(--text-white);
}

.hero h1 {
    color: var(--primary-lime);
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto;
    color: var(--text-muted);
}

/* Main Container */
.container {
    max-width: 1200px;
    margin: -3rem auto 4rem;
    padding: 0 5%;
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 2rem;
}

/* Input Section */
.inputs {
    background: #fff;
    padding: 2.5rem;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

.input-group {
    margin-bottom: 2rem;
}

.input-group label {
    display: block;
    font-weight: 700;
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
}

.input-wrapper span {
    position: absolute;
    left: 1rem;
    font-weight: 600;
    color: #666;
}

.input-wrapper input[type="number"] {
    width: 100%;
    padding: 0.8rem 1rem 0.8rem 2rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--input-bg);
    font-size: 1.1rem;
    font-weight: 600;
    outline: none;
}

.input-wrapper input:focus {
    border-color: var(--primary-lime);
}

.slider-container {
    padding: 0.5rem 0;
}

input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    background: #e0e0e0;
    border-radius: 5px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: var(--primary-lime);
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid #fff;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.input-desc {
    font-size: 0.85rem;
    color: #666;
    margin-top: 0.5rem;
}

/* Results Section */
.results {
    position: sticky;
    top: 2rem;
    height: fit-content;
}

.result-card {
    background: #fff;
    padding: 2.5rem;
    border-radius: 8px;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.08);
    text-align: center;
}

.metric {
    margin-bottom: 2.5rem;
}

.metric:last-child {
    margin-bottom: 0;
}

.metric-label {
    display: block;
    font-weight: 700;
    font-size: 0.9rem;
    color: #666;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 0.5rem;
}

.metric-value {
    display: block;
    font-size: 2.5rem;
    font-weight: 900;
    color: #121212;
}

.positive {
    color: #28a745;
}

.savings {
    background: #f8fff0;
    border: 2px solid var(--primary-lime);
    padding: 1.5rem;
    border-radius: 8px;
}

.savings .metric-value {
    color: #121212;
}

/* Info Sections (Keep in Mind / Need assistance) */
.info-sections {
    background: #fff;
    padding: 4rem 5%;
    border-top: 1px solid var(--border-color);
}

.info-container {
    max-width: 1200px;
    margin: 0 auto;
}

.info-container h2 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: #333;
}

.keep-in-mind {
    margin-bottom: 3rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 3rem;
}

.keep-in-mind p {
    color: #555;
    font-size: 1rem;
    line-height: 1.6;
}

.assistance h2 {
    margin-bottom: 2rem;
}

.cta-grid {
    display: flex;
    gap: 1.5rem;
}

.cta-grid .btn {
    flex: 1;
    text-align: center;
    padding: 1rem 1.5rem;
    font-size: 1.1rem;
    font-weight: 700;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.btn-dark {
    background: #374151;
    /* gray-700 */
    color: #fff;
}

.btn-dark:hover {
    background: #1f2937;
    /* gray-800 */
}

.btn-lime {
    background: #84cc16;
    /* green-500 inspired */
    color: #111827;
    /* gray-900 */
}

.btn-lime:hover {
    background: #84cc16;
    /* green-500 inspired */
}

/* Footer */
footer {
    background: #fff;
    text-align: center;
    padding: 2rem;
    font-size: 0.9rem;
    color: #888;
    border-top: 1px solid var(--border-color);
}

/* Responsive */
@media (max-width: 992px) {
    .container {
        grid-template-columns: 1fr;
        margin-top: 0;
    }

    .results {
        position: static;
    }

    .hero {
        padding: 3rem 5%;
    }

    .hero h1 {
        font-size: 2.2rem;
    }

    .cta-grid {
        flex-direction: column;
    }
}